(1) Field of the Invention
The present invention relates to a novel building construction, and more particularly relates to an arrangement for joining columns and beams of concrete to provide junctions in framework structures for buildings and the like.
(2) State of the Prior Art
In building constructions consisting of concrete columns interconnected with concrete beams, the concrete columns are usually provided with lateral projections or brackets or consoles at each floor level for support of the beams. Such provision makes possible a quick erection of the building structure frames, and the beams can be given a length equal to the distance between the respective columns.
Lateral projections on the columns are, however, usually not desirable, since they complicate production, storage and transport, complicate the laying of cables and lines, and in many cases can result in corner terminations in the building which hinder interior installations. In order to avoid lateral projections the consoles can be made sufficiently low vertically, so that they are incorporated in the vertical dimensions of the beam and floor structure, but such a solution may weaken the load capacity of the structure and complicate the subsequent mounting of floor decks between the beams.
A further disadvantage with conventional console arrangements is that, in connection with the erection, there is not obtained a rigid and self supporting structure. As a remedy for these shortcomings there are used various types of joint strengthening provisions but such arrangements necessitate steps, such as bolting, welding or moulding, which lead to larger costs and delays the building work with the same result.
A further disadvantage with console columns is that the columns must be produced and delivered with pre-designed consoles in order to fit into the building in question, and in many cases one must remove consoles which are not being used. The need can arise for up to four consoles at each floor level, but in many cases there is only needed one or two consoles. This technique has led to steadily more complicated columns with consoles both in three and four directions at each floor level.
In order to avoid the use of columns with pre-fabricated consoles there has been developed several solutions for so called "console free" columns, wherein pre-fabricated concrete consoles are replaced with imbedded fittings usually, made of steel, and positioned in opposing parts of the columns and beams at each floor level in the junctions, or so called "nodes". These complementary fittings in the columns and beams, respectively, are put into engagement with each other during the mounting by means of bolts, welding or in other ways.
Illustrative of this technique is German published application No. 1,914,298. In the shown arrangement are utilized two pairs of imbedded fittings at each joint between a beam and a column. The fittings present, however, lateral console-like parts which are easily damaged during transport and otherwise possess several of the shortcomings already described. The positioning and mounting of the beams requires further welding, as well as moulding. In another known solution, boxlike fittings are imbedded in the column during the production of the column. On the building site a console is mounted into the box fitting by means of bolts, whereafter the beams may be positioned in place when the columns have been erected. The beam is thereafter fastened by means of bolts and a moulding operation.